US4435667A - Spiral piezoelectric rotary actuator - Google Patents

Spiral piezoelectric rotary actuator Download PDF

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Publication number
US4435667A
US4435667A US06372636 US37263682A US4435667A US 4435667 A US4435667 A US 4435667A US 06372636 US06372636 US 06372636 US 37263682 A US37263682 A US 37263682A US 4435667 A US4435667 A US 4435667A
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US
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Grant
Patent type
Prior art keywords
rotary actuator
rotatable member
piezoelectric
leaf spring
member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06372636
Inventor
Henry H. Kolm
Eric A. Kolm
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PIEZOELECTRIC PRODUCTS Inc A CORP OF
PEIZO ELECTRIC PRODUCTS Inc
Original Assignee
PEIZO ELECTRIC PRODUCTS Inc
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Filing date
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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02NELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N2/00Electric machines in general using piezo-electric effect, electrostriction or magnetostriction
    • H02N2/10Electric machines in general using piezo-electric effect, electrostriction or magnetostriction producing rotary motion, e.g. rotary motors
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01HMEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H1/00Measuring characteristics of vibrations in solids by using direct conduction to the detector
    • G01H1/10Measuring characteristics of vibrations in solids by using direct conduction to the detector of torsional vibrations
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L41/00Piezo-electric devices in general; Electrostrictive devices in general; Magnetostrictive devices in general; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L41/08Piezo-electric or electrostrictive devices
    • H01L41/09Piezo-electric or electrostrictive devices with electrical input and mechanical output, e.g. actuators, vibrators
    • H01L41/0926Piezo-electric or electrostrictive devices with electrical input and mechanical output, e.g. actuators, vibrators using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
    • H01L41/0933Beam type
    • H01L41/094Cantilevers, i.e. having one fixed end
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S310/00Electrical generator or motor structure
    • Y10S310/80Piezoelectric polymers, e.g. PVDF

Abstract

A piezoelectric rotary actuator including: a rotatable member; a spiral member fixed at its inner end to the rotatable member; one or more piezoelectric layers attached on one or both sides of the spiral member; means for rotatably supporting the rotatable member relative to the outer portion of the spiral member; and an electrode for applying a voltage across the piezoelectric layer or layers, to bend the spiral and rotate the rotatable member.

Description

FIELD OF INVENTION

This invention relates to a piezoelectric rotary actuator or motor, and more particularly to such a rotary actuator which utilizes a piezoelectric spiral member.

BACKGROUND OF INVENTION

Piezoelectric materials make very efficient and fast-acting electro-mechanical energy converters or transducers. Piezoceramics have been used as transducers for several years, but mostly in a resonant mode. Examples of application include underwater sound transducers for echo ranging and submarine detection, transducers for ultrasonic washing, milling, cutting and welding machines, transducers for medical acoustic imaging devices, sound generators for alarms, and high frequency loudspeakers. There are some applications in which piezoceramics have been used to produce discrete motion rather than oscillatory motion. Due to the very small dimensional change produced in simple piezoelectric bodies, special configurations have been developed for the purpose of achieving the largest possible dimensional change. One type of actuating element is a so-called "stack motor", which is a stack of many individual piezoceramic wafers connected mechanically in series and electrically in parallel so as to generate the largest possible expansion and contraction without the need for unreasonably high voltages. Stack motors are relatively quite expensive. Another type of piezoelectric actuating element developed for achieving large motion is known generally as a "bender" or "bimorph" or "bilam". A bender consists of one or more piezoceramic wafers several mils thick, fired and polarized, and then bonded to a metal support sheet. In symmetric benders, the metal support sheet is along the neutral axis, where neither compression or expansion occurs, and is flanked by two or more piezoceramic wafers, polarized and energized in such a manner that the wafers on one side of the support sheet contract, while those on the other side expand, thereby causing the element to bend when a voltage is applied to its electrodes. Bending motion, however, is limited to a small fraction of the length of the bender, about 20 mils in the case of a bender 1.5 inches long. This limitation is due to the brittleness of the piezoceramic wafers. There is no practical method for producing large motion strokes, in particular large rotary motion strokes, by means of a piezoceramic element. Rotary electric actuators have therefore been of the magnetic type, and magentic motors are vastly less energy-efficient than piezoelectric motors and become increasingly less efficient as they are scaled down to smaller and smaller size.

SUMMARY OF INVENTION

It is therefore an object of this invention to provide an improved, simpler and less expensive rotary actuator.

It is a further object of this invention to provide such a rotary actuator which provides a large-stroke rotary motion.

It is a further object of this invention to provide such a rotary actuator which is highly efficient and may be arbitrarily small in size.

It is a further object of this invention to provide such a rotary actuator which employs a piezoelectric medium.

This invention results from the realization that a truly effective rotary actuator can be constructed using a flexible piezoelectric medium in combination with a spiral member such as a coiled leaf spring which when properly energized may be made to bend into a tighter or more expanded coil and rotate a shaft at its inner end.

The invention features a piezoelectric rotary actuator including a rotatable member and a spiral member fixed at its inner or outer end to the rotatable member. One or more piezoelectric layers are attached to the spiral member and electrode means are provided for applying a voltage across the piezoelectric layer or layers to bend the spiral member and rotate the rotatable member.

In a preferred embodiment, the rotatable member is a shaft and the spiral member is a spring, and more particularly is a leaf spring formed in a coil such as a watch spring. The piezoelectric layer may be made of a granular piezoceramic material in an elastomeric binder. The elastomeric binder may be vinyl. The electrode means may include an electrode on the free side of the piezoelectric layers and the spiral member may be made of electrically conducting material and constitute a common electrode. There may be two or more piezoelectric layers, with electrodes between layers, so that the piezoelectric layers can be connected electrically in parallel for the purpose of keeping the operating voltage at a minimum.

DISCLOSURE OF PREFERRED EMBODIMENT

Other objects, features and advantages will occur from the following description of a preferred embodiment and the accompanying drawings, in which:

FIG. 1 is an axonometric diagram of a piezoelectric rotary actuator according to this invention;

FIG. 2 is an enlarged cross-sectional view of the coil member of FIG. 1;

FIG. 3 is an enlarged cross-sectional view similar to FIG. 2 of an alternative embodiment having two piezoelectric layers;

FIG. 4 is a top plan view of the rotary actuator of FIG. 1 energized to bend the coil member to the expanded state;

FIG. 5 is a view similar to FIG. 4 with the coil member energized to the contracted state;

FIG. 6 is a side elevational cross-sectional view of an alternative construction of the rotary actuator according to this invention;

FIG. 7 is a cross-sectional view through the shaft of FIG. 6 showing the attachment of the coil member to the shaft; and

FIG. 8 is an axonometric view, partially in section, of the rotary actuator of FIG. 6.

The invention may be accomplished with a piezoelectric rotary actuator including a rotatable member such as a shaft and a coil member which includes a spiral member fixed at its inner end to the shaft, and a piezoelectric layer attached on one side to the spiral member. Alternatively, the spiral member may be attached at its inner end to the fixed member and at its outer end to the rotatable member, as is often the construction in clock mechanisms. The spiral member is typically a leaf spring similar to a coil spring or watch spring. The piezoelectric layer is a flexible elastic layer made, for example, by crushing a fired body of piezoceramic material such as lead zirconate-lead titanate, crushing it to granules of one to ten micron size, mixing the granulated piezoceramic with an elastomeric medium such as vinyl, coating the vinyl onto the leaf spring in a layer 0.5 mm thick, applying an electrode coating to the outer surface of the vinyl layer, and the polarizing the layer by applying a voltage of 1,000 volts across the layer in an oil bath.

The coiled leaf spring may act as a second electrode. A voltage applied across the electrode bends the spiral member, either inwardly to contract or outwardly to expand, and rotates the shaft in the clockwise or counterclockwise direction. If the coil spring with the piezoceramic layer has a length of twelve inches, the shaft will rotate through an angle of about forty-five degrees upon the application of about 300 volts across the electrodes. The rotary actuator is useful in many applications; for example as an action for a volt meter it has substantially less resistive loss and substantially higher input impedance than the magnetically driven volt meter movement. It is also less expensive and more rugged than the typical galvanometer movement used in many volt meters.

There is shown in FIG. 1 a piezoelectric rotary actuator 10 according to this invention having a coil member 12 with its inner end 14 fixed to shaft 16 rotatably mounted in support plate 18. Outer end 20 of coil member 12 is fixed by means such as anchor blocks 22, 24 to support plate 18. Coil member 12 is energized to bend to contract and drive shaft 16 in one direction, or to bend and expand and drive shaft 16 in the opposite direction, by a voltage applied to wires 26, 28.

Coil member 12, FIG. 2, is comprised of a coiled or spiral leaf spring 30, FIG. 2, on which is supported the piezoceramic-vinyl flexible piezoelectric layer 32. An electrode 34 such as silver plating, applied by means of vacuum deposition or electroplating from aqueous solution in a coating 0.0001 inch thick, is applied to the free side of piezoelectric layer 32. Wires 28 and 26 are soldered at 36, 38 to spring 30 and electrode 34. If spring 30 is not a metal or other electrical conducting material, a second electrode may be used between spring 30 and piezoelectric layer 32. With piezoelectric layer 32 polarized as shown with its side toward electrode 34 positive and its slide toward spring 30 negative, a voltage applied to wires 28 and 26 having a positive polarity at wire 28 and a negative polarity at 26, i.e., in the poling direction, causes piezoelectric layer 32 to contract longitudinally, causing the spring member to uncoil.

Alternatively, as shown in FIG. 3, coil member 12a may include two piezoelectric layers 32a, 32b, on either side of spring 30a. Each piezoelectric layer 32a, 32b is provided with an electrode 34a, 34b on its free side which interconnects with wires 26a, 28b the solder joints 36a, 38a, respectively.

In operation, an application of 300 volts-positive to wire 28, negative to wire 26, FIG. 4, coil 12 bends to the expanded position with the marker 50 on shaft 16 pointing toward the twelve o'clock position. Shaft 16 is rotatably mounted in bearing hole 52 of support plate 18 for rotation about center axis 54. A reversal of the applied voltage: the application of 300 volts positive to wire 26, negative to wire 28, FIG. 5, bends coil 12 to its contracted position and rotates shaft 16 about ninety degrees, as indicated by the new location of marker 50 at the three o'clock position.

A simple construction of a piezoelectric rotary actuator according to this invention is shown in FIG. 6, where a shaft 16c is rotatably mounted in bearings 60, 62, FIG. 8, in housing 64. Other end 20c of coil member 12c is attached to housing 64 by means of rivets 66, 68. Both ends 70, 72 extend beyond housing 64 and are accessible for attachment to equipment to be driven. Inner end 14c, FIG. 7, of coil 12c is received in slot 74 of shaft 16c and is fixed there by means of rivets 76 and 78.

Other embodiments will occur to those skilled in the art and are within the following claims:

Claims (12)

What is claimed is:
1. A piezoelectric rotary actuator comprising: a rotatable member; a fixed member; a spiral leaf spring attached at one end to said rotatable member and at the other end to said fixed member; a piezoelectric layer attached on one side to said spiral leaf spring; and electrode means for applying a voltage across said piezoelectric layer to bend said spiral leaf spring and rotate said rotatable member.
2. The rotary actuator of claim 1 in which said rotatable member is a shaft.
3. The rotary actuator of claim 1 in which said piezoelectric layer is made of a granular piezoceramic material in an elastomeric binder.
4. The rotary actuator of claim 3 in which said elastomeric binder is vinyl.
5. The rotary actuator of claim 1 in which said electrode means includes an electrode on the free side of said piezoelectric layer and said spiral leaf spring is made of electrically conducting material and constitutes a second electrode.
6. The rotary actuator of claim 1 further including a second piezoelectric layer attached to the other side of said spiral leaf spring and said electrode means including a second electrode attached to the free side of said second piezoelectric layer.
7. The rotary actuator of claim 1 in which said spiral leaf spring is attached at its inner end to said rotatable member.
8. A piezoelectric rotary actuator comprising:
a rotatable member; a fixed member; a spiral leaf spring attached at its inner end to said rotatable member and at its outer end to said fixed member; first and second piezoelectric layers attached to opposite sides of said spiral leaf spring; and electrode means for applying a voltage across said piezoelectric layers to bend said spiral leaf spring and rotate said rotatable member.
9. The rotary actuator of claim 8 in which said rotatable member is a shaft.
10. The rotary actuator of claim 8 in which piezoelectric layer is made of a granular piezoceramic in an elastomeric binder.
11. The rotary actuator of claim 10 in which said elastomeric binder is vinyl.
12. The rotary actuator of claim 8 in which said spiral leaf spring is attached at its inner end to said rotatable member.
US06372636 1982-04-28 1982-04-28 Spiral piezoelectric rotary actuator Expired - Fee Related US4435667A (en)

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US06372636 US4435667A (en) 1982-04-28 1982-04-28 Spiral piezoelectric rotary actuator

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Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0160707A1 (en) * 1984-05-03 1985-11-13 International Business Machines Corporation Piezoelectric stepping rotator
GB2219171A (en) * 1988-04-08 1989-11-29 Pennwalt Piezo Film "Vibration sensor"
US5126615A (en) * 1990-05-01 1992-06-30 Ngk Insulators, Ltd. Piezoelectric/electrostrictive actuator having at least one piezoelectric/electrostrictive film
US5159405A (en) * 1989-10-28 1992-10-27 Horiba, Ltd. Multibeam interferometer for use in a fourier transform spectrometer and a driving device for moving the mirrors used therein
US5440194A (en) * 1994-05-13 1995-08-08 Beurrier; Henry R. Piezoelectric actuators
US5626312A (en) * 1994-07-06 1997-05-06 Mcdonnell Douglas Corporation Piezoelectric actuator
US5703425A (en) * 1993-01-29 1997-12-30 Thomson-Csf Process for manufacturing a piezoelectric component
US5977685A (en) * 1996-02-15 1999-11-02 Nitta Corporation Polyurethane elastomer actuator
WO2002078053A2 (en) * 2001-03-27 2002-10-03 1...Limited Electro-active rotary device
US6545391B1 (en) * 1999-10-22 2003-04-08 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Polymer-polymer bilayer actuator
US6671380B2 (en) * 2001-02-26 2003-12-30 Schlumberger Technology Corporation Acoustic transducer with spiral-shaped piezoelectric shell
US20040017129A1 (en) * 1999-12-21 2004-01-29 Anthony Hooley Electro active devices
US6713944B2 (en) * 2002-01-02 2004-03-30 Omron Corporation Actuator and method of manufacturing a strain element
US6734603B2 (en) * 1995-04-04 2004-05-11 The United States Of America As Represented By The National Aeronautics And Space Administration Thin layer composite unimorph ferroelectric driver and sensor
US20040201331A1 (en) * 2003-01-10 2004-10-14 Southwest Research Institute Polymer film composite transducer
US20040217671A1 (en) * 2001-05-22 2004-11-04 Sri International, A California Corporation Rolled electroactive polymers
US20040237676A1 (en) * 2001-06-20 2004-12-02 Mckevitt Gareth Sensor using electro active curved helix and double helix
US20050074134A1 (en) * 2001-04-03 2005-04-07 Pearce David Henry Actuator assembly
US6960864B2 (en) * 2001-12-25 2005-11-01 Matsushita Electric Works, Ltd. Electroactive polymer actuator and diaphragm pump using the same
US20090124994A1 (en) * 2007-11-08 2009-05-14 Roe Steven N Miniature drug delivery pump with a piezoelectric drive system
US7696673B1 (en) 2006-12-07 2010-04-13 Dmitriy Yavid Piezoelectric generators, motor and transformers
US20100186560A1 (en) * 2006-02-03 2010-07-29 Konrad Tzschentke Apparatus and method for controlling the machining of workpieces using piezoceramic transducers
US20110018397A1 (en) * 2009-07-21 2011-01-27 Murata Manufacturing, Co., Ltd. Piezoelectric Power Generation Device
WO2011131784A1 (en) 2010-04-21 2011-10-27 Team Smartfish Gmbh Controller for a clockwork mechanism, and corresponding method
US20130107677A1 (en) * 2011-10-28 2013-05-02 The Swatch Group Research And Development Ltd. Circuit for autoregulating the oscillation frequency of an oscillating mechanical system and device including the same
DE102008036760B4 (en) * 2008-08-07 2014-04-24 Eurocopter Deutschland Gmbh rotor blade
US9195058B2 (en) 2011-03-22 2015-11-24 Parker-Hannifin Corporation Electroactive polymer actuator lenticular system
US9231186B2 (en) 2009-04-11 2016-01-05 Parker-Hannifin Corporation Electro-switchable polymer film assembly and use thereof
US9425383B2 (en) 2007-06-29 2016-08-23 Parker-Hannifin Corporation Method of manufacturing electroactive polymer transducers for sensory feedback applications
US9553254B2 (en) 2011-03-01 2017-01-24 Parker-Hannifin Corporation Automated manufacturing processes for producing deformable polymer devices and films
US9590193B2 (en) 2012-10-24 2017-03-07 Parker-Hannifin Corporation Polymer diode
US9761790B2 (en) 2012-06-18 2017-09-12 Parker-Hannifin Corporation Stretch frame for stretching process
US9876160B2 (en) 2012-03-21 2018-01-23 Parker-Hannifin Corporation Roll-to-roll manufacturing processes for producing self-healing electroactive polymer devices

Cited By (56)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4600854A (en) * 1984-03-05 1986-07-15 International Business Machines Corp. Piezoelectric stepping rotator
EP0160707A1 (en) * 1984-05-03 1985-11-13 International Business Machines Corporation Piezoelectric stepping rotator
GB2219171A (en) * 1988-04-08 1989-11-29 Pennwalt Piezo Film "Vibration sensor"
GB2219171B (en) * 1988-04-08 1991-11-20 Pennwalt Piezo Film Vibration sensor
US5159405A (en) * 1989-10-28 1992-10-27 Horiba, Ltd. Multibeam interferometer for use in a fourier transform spectrometer and a driving device for moving the mirrors used therein
US5126615A (en) * 1990-05-01 1992-06-30 Ngk Insulators, Ltd. Piezoelectric/electrostrictive actuator having at least one piezoelectric/electrostrictive film
US5703425A (en) * 1993-01-29 1997-12-30 Thomson-Csf Process for manufacturing a piezoelectric component
US5440194A (en) * 1994-05-13 1995-08-08 Beurrier; Henry R. Piezoelectric actuators
US5626312A (en) * 1994-07-06 1997-05-06 Mcdonnell Douglas Corporation Piezoelectric actuator
US6734603B2 (en) * 1995-04-04 2004-05-11 The United States Of America As Represented By The National Aeronautics And Space Administration Thin layer composite unimorph ferroelectric driver and sensor
US5977685A (en) * 1996-02-15 1999-11-02 Nitta Corporation Polyurethane elastomer actuator
US6545391B1 (en) * 1999-10-22 2003-04-08 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Polymer-polymer bilayer actuator
US20040017129A1 (en) * 1999-12-21 2004-01-29 Anthony Hooley Electro active devices
US6833656B2 (en) * 1999-12-21 2004-12-21 1 . . . Limited Electro active devices
US6671380B2 (en) * 2001-02-26 2003-12-30 Schlumberger Technology Corporation Acoustic transducer with spiral-shaped piezoelectric shell
WO2002078053A3 (en) * 2001-03-27 2003-09-25 1 Ltd Electro-active rotary device
WO2002078053A2 (en) * 2001-03-27 2002-10-03 1...Limited Electro-active rotary device
GB2390481B (en) * 2001-03-27 2004-08-04 1 Ltd Electro-active rotary device
GB2390481A (en) * 2001-03-27 2004-01-07 1 Ltd Electro-active rotary device
US20050074134A1 (en) * 2001-04-03 2005-04-07 Pearce David Henry Actuator assembly
US8042264B2 (en) 2001-05-22 2011-10-25 Sri International Method of fabricating an electroactive polymer transducer
US20110025170A1 (en) * 2001-05-22 2011-02-03 Sri International Electroactive polymer device
US20040217671A1 (en) * 2001-05-22 2004-11-04 Sri International, A California Corporation Rolled electroactive polymers
US20100263181A1 (en) * 2001-05-22 2010-10-21 Sri International Rolled electroactive polymers
US8093783B2 (en) 2001-05-22 2012-01-10 Sri International Electroactive polymer device
US20090184606A1 (en) * 2001-05-22 2009-07-23 Sri International Rolled electroactive polymers
US20080022517A1 (en) * 2001-05-22 2008-01-31 Sri International Rolled electroactive polymers
US7233097B2 (en) * 2001-05-22 2007-06-19 Sri International Rolled electroactive polymers
US7761981B2 (en) 2001-05-22 2010-07-27 Sri International Methods for fabricating an electroactive polymer device
US7069795B2 (en) * 2001-06-20 2006-07-04 1...Limited Sensor using electro active curved helix and double helix
US20040237676A1 (en) * 2001-06-20 2004-12-02 Mckevitt Gareth Sensor using electro active curved helix and double helix
US6960864B2 (en) * 2001-12-25 2005-11-01 Matsushita Electric Works, Ltd. Electroactive polymer actuator and diaphragm pump using the same
US6713944B2 (en) * 2002-01-02 2004-03-30 Omron Corporation Actuator and method of manufacturing a strain element
US20040135475A1 (en) * 2002-01-02 2004-07-15 Nobuaki Omata Actuator and method of manufacturing a strain element
US6983521B2 (en) 2002-01-02 2006-01-10 Omron Corporation Method of manufacturing a strain element
US20040201331A1 (en) * 2003-01-10 2004-10-14 Southwest Research Institute Polymer film composite transducer
US6946777B2 (en) * 2003-01-10 2005-09-20 Southwest Research Institute Polymer film composite transducer
US20100186560A1 (en) * 2006-02-03 2010-07-29 Konrad Tzschentke Apparatus and method for controlling the machining of workpieces using piezoceramic transducers
US7696673B1 (en) 2006-12-07 2010-04-13 Dmitriy Yavid Piezoelectric generators, motor and transformers
US9425383B2 (en) 2007-06-29 2016-08-23 Parker-Hannifin Corporation Method of manufacturing electroactive polymer transducers for sensory feedback applications
US7592740B2 (en) 2007-11-08 2009-09-22 Roche Diagnostics Operations, Inc. Miniature drug delivery pump with a piezoelectric drive system
US20090124994A1 (en) * 2007-11-08 2009-05-14 Roe Steven N Miniature drug delivery pump with a piezoelectric drive system
DE102008036760B4 (en) * 2008-08-07 2014-04-24 Eurocopter Deutschland Gmbh rotor blade
US9231186B2 (en) 2009-04-11 2016-01-05 Parker-Hannifin Corporation Electro-switchable polymer film assembly and use thereof
US8344598B2 (en) 2009-07-21 2013-01-01 Murata Manufacturing Co., Ltd. Piezoelectric power generation device
US20110018397A1 (en) * 2009-07-21 2011-01-27 Murata Manufacturing, Co., Ltd. Piezoelectric Power Generation Device
US8334638B2 (en) * 2009-07-21 2012-12-18 Murata Manufacturing Co., Ltd. Piezoelectric power generation device
US8721169B2 (en) 2010-04-21 2014-05-13 Team Smartfish Gmbh Controller for a clockwork mechanism, and corresponding method
WO2011131784A1 (en) 2010-04-21 2011-10-27 Team Smartfish Gmbh Controller for a clockwork mechanism, and corresponding method
US9553254B2 (en) 2011-03-01 2017-01-24 Parker-Hannifin Corporation Automated manufacturing processes for producing deformable polymer devices and films
US9195058B2 (en) 2011-03-22 2015-11-24 Parker-Hannifin Corporation Electroactive polymer actuator lenticular system
US20130107677A1 (en) * 2011-10-28 2013-05-02 The Swatch Group Research And Development Ltd. Circuit for autoregulating the oscillation frequency of an oscillating mechanical system and device including the same
US9188957B2 (en) * 2011-10-28 2015-11-17 The Swatch Group Research And Development Ltd. Circuit for autoregulating the oscillation frequency of an oscillating mechanical system and device including the same
US9876160B2 (en) 2012-03-21 2018-01-23 Parker-Hannifin Corporation Roll-to-roll manufacturing processes for producing self-healing electroactive polymer devices
US9761790B2 (en) 2012-06-18 2017-09-12 Parker-Hannifin Corporation Stretch frame for stretching process
US9590193B2 (en) 2012-10-24 2017-03-07 Parker-Hannifin Corporation Polymer diode

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